added iOS source code

[wl-app.git] / iOS / WolneLektury / Screens / NewsDetails / Gallery / Cells / GalleryCell.swift

diff --git a/iOS/WolneLektury/Screens/NewsDetails/Gallery/Cells/GalleryCell.swift b/iOS/WolneLektury/Screens/NewsDetails/Gallery/Cells/GalleryCell.swift
new file mode 100644 (file)
index 0000000..f1d1c4d
--- /dev/null
+++ b/iOS/WolneLektury/Screens/NewsDetails/Gallery/Cells/GalleryCell.swift
@@ -0,0 +1,168 @@
+//
+//  GalleryCell.swift
+//  WolneLektury
+//
+//  Created by Pawel Dabrowski on 17/09/2018.
+//  Copyright © 2018 Fundacja Nowoczesna Polska. All rights reserved.
+//
+
+import UIKit
+import Kingfisher
+import MBProgressHUD
+
+public class GalleryCell: UICollectionViewCell {
+    
+    var url: String?{
+        didSet {
+            configureForNewImageUrl()
+        }
+    }
+    
+    private var scrollView: UIScrollView
+    fileprivate let imageView: UIImageView
+    var progressHud: MBProgressHUD?
+    
+    func setScrollEnabled(scrollEnabled: Bool){
+        scrollView.isUserInteractionEnabled = scrollEnabled
+        if !scrollEnabled{
+            setZoomScale()
+        }
+    }
+    
+    override init(frame: CGRect) {
+        
+        imageView = UIImageView()
+        imageView.translatesAutoresizingMaskIntoConstraints = false
+        scrollView = UIScrollView(frame: frame)
+        scrollView.translatesAutoresizingMaskIntoConstraints = false
+        scrollView.backgroundColor = Constants.Colors.darkGreenBgColor()
+        super.init(frame: frame)
+        
+        var scrollViewConstraints: [NSLayoutConstraint] = []
+        var imageViewConstraints: [NSLayoutConstraint] = []
+        
+        scrollViewConstraints.append(NSLayoutConstraint(item: scrollView, attribute: .leading, relatedBy: .equal, toItem: contentView, attribute: .leading, multiplier: 1, constant: 0))
+        scrollViewConstraints.append(NSLayoutConstraint(item: scrollView, attribute: .top, relatedBy: .equal, toItem: contentView, attribute: .top, multiplier: 1, constant: 0))
+        scrollViewConstraints.append(NSLayoutConstraint(item: scrollView, attribute: .trailing, relatedBy: .equal, toItem: contentView, attribute: .trailing, multiplier: 1, constant: 0))
+        scrollViewConstraints.append(NSLayoutConstraint(item: scrollView, attribute: .bottom, relatedBy: .equal, toItem: contentView, attribute: .bottom, multiplier: 1, constant: 0))
+        contentView.addSubview(scrollView)
+        contentView.addConstraints(scrollViewConstraints)
+        
+        imageViewConstraints.append(NSLayoutConstraint(item: imageView, attribute: .leading, relatedBy: .equal, toItem: scrollView, attribute: .leading, multiplier: 1, constant: 0))
+        imageViewConstraints.append(NSLayoutConstraint(item: imageView, attribute: .top, relatedBy: .equal, toItem: scrollView, attribute: .top, multiplier: 1, constant: 0))
+        imageViewConstraints.append(NSLayoutConstraint(item: imageView, attribute: .trailing, relatedBy: .equal, toItem: scrollView, attribute: .trailing, multiplier: 1, constant: 0))
+        imageViewConstraints.append(NSLayoutConstraint(item: imageView, attribute: .bottom, relatedBy: .equal, toItem: scrollView, attribute: .bottom, multiplier: 1, constant: 0))
+        scrollView.addSubview(imageView)
+        scrollView.addConstraints(imageViewConstraints)
+
+        scrollView.delegate = self
+        
+        let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(tapGestureRecognizerAction(recognizer:)))
+        tapGestureRecognizer.numberOfTapsRequired = 2
+        self.addGestureRecognizer(tapGestureRecognizer)
+    }
+    
+    @objc public func tapGestureRecognizerAction(recognizer: UITapGestureRecognizer) {
+        if (scrollView.zoomScale > scrollView.minimumZoomScale) {
+            scrollView.setZoomScale(scrollView.minimumZoomScale, animated: true)
+        } else {
+            scrollView.setZoomScale(scrollView.maximumZoomScale, animated: true)
+        }
+    }
+
+    required public init?(coder aDecoder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    public func configureForNewImageUrl() {
+        
+        guard let imageUrl = url?.getPhotoUrl() else{
+            self.setupImage(image: nil)
+            return
+        }
+        
+        if progressHud == nil{
+            progressHud = MBProgressHUD.showAdded(to: contentView, animated: true)
+            progressHud?.label.text = "loading".localized
+        }
+        else{
+            progressHud?.show(animated: true)
+        }
+        
+        //        let freeSpace = contentView.bounds.size.height - textContainerHeight
+        let contentOffsetY = ((contentView.bounds.size.height/2 /*- freeSpace/2*/) * -1)
+        progressHud!.offset.y = contentOffsetY
+        
+        KingfisherManager.shared.retrieveImage(with: ImageResource(downloadURL: imageUrl), options: nil, progressBlock: nil) { (image, error, cacheType, url) in
+            self.progressHud?.hide(animated: true)
+            self.setupImage(image: image)
+        }
+    }
+
+    
+    // ############################################
+    // MARK: - Private
+    // ############################################
+    
+    private func setupImage(image: UIImage?){
+        imageView.image = image
+        imageView.sizeToFit()
+        imageView.alpha = 0.0
+        
+        setZoomScale()
+        scrollViewDidZoom(scrollView)
+        
+        UIView.animate(withDuration: 0.5) {
+            self.imageView.alpha = 1.0
+        }
+    }
+    
+    private func setZoomScale() {
+        
+        let imageViewSize = imageView.bounds.size
+        
+        guard imageViewSize.width > 0 && imageViewSize.height > 0 else {
+            return
+        }
+        
+        let scrollViewSize =  UIScreen.main.bounds.size// scrollView.bounds.size
+        let widthScale = scrollViewSize.width / imageViewSize.width
+        let heightScale = scrollViewSize.height / imageViewSize.height
+        let miminumZoomScale = min(widthScale, heightScale)
+        scrollView.minimumZoomScale = miminumZoomScale
+        
+        let initialZoomScale = max(widthScale, heightScale)
+        
+        scrollView.maximumZoomScale = initialZoomScale * 1.5
+        
+        scrollView.setZoomScale(miminumZoomScale, animated: false)
+        
+        let newContentOffsetX = (scrollView.contentSize.width/2) - (scrollView.bounds.size.width/2);
+        
+        scrollView.contentOffset = CGPoint(x: newContentOffsetX, y: scrollView.contentOffset.y)
+    }
+}
+
+extension GalleryCell: UIScrollViewDelegate {
+    
+    public func viewForZooming(in scrollView: UIScrollView) -> UIView? {
+        return imageView
+    }
+    
+    public func scrollViewDidZoom(_ scrollView: UIScrollView) {
+        
+        let imageViewSize = imageView.frame.size
+        let scrollViewSize = scrollView.bounds.size
+        
+        let verticalPadding = imageViewSize.height < scrollViewSize.height ? (scrollViewSize.height - imageViewSize.height) / 2 : 0
+        let horizontalPadding = imageViewSize.width < scrollViewSize.width ? (scrollViewSize.width - imageViewSize.width) / 2 : 0
+        
+        if verticalPadding >= 0 {
+            // Center the image on screen
+            scrollView.contentInset = UIEdgeInsets(top: verticalPadding, left: horizontalPadding, bottom: verticalPadding, right: horizontalPadding)
+        } else {
+            // Limit the image panning to the screen bounds
+            scrollView.contentSize = imageViewSize
+        }
+    }
+}